import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
-import org.eclipse.linuxtools.tmf.core.component.ITmfComponent;
+import org.eclipse.linuxtools.tmf.core.component.ITmfDataProvider;
import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
import org.eclipse.linuxtools.tmf.core.event.ITmfTimestamp;
import org.eclipse.linuxtools.tmf.core.event.TmfTimeRange;
/**
* <b><u>ITmfTrace</u></b>
* <p>
- * The basic event trace structure in TMF.
+ * The event stream structure in TMF. In its basic form, a trace has:
+ * <ul>
+ * <li> the associated Eclipse resource
+ * <li> the path to its location on the file system
+ * <li> the type of the events it contains
+ * <li> the number of events it contains
+ * <li> the time range (span) of the events it contains
+ * </ul>
+ * Concrete ITmfTrace classes have to provide a parameter-less constructor and
+ * an initialization method (initTace())if they are to be opened from the
+ * Project View. Also, a validation (validate()) method has to be provided to
+ * ensure that the trace is of the correct type.
+ * <p>
+ * A trace can be accessed simultaneously from multiple threads by various
+ * application components. To avoid obvious multi-threading issues, the trace
+ * uses an ITmfContext as a synchronization aid for its read operations.
+ * <p>
+ * A proper ITmfContext can be obtained by performing a seek operation on the
+ * trace. Seek operations can be performed for a particular event (by rank or
+ * timestamp) or for a plain trace location.
+ * <p>
+ * <b>Example 1</b>: Read a whole trace
+ * <pre>
+ * ITmfContext context = trace.seekLocationt(null);
+ * ITmfEvent event = trace.getEvent(context);
+ * while (event != null) {
+ * // Do something ...
+ * event = trace.getEvent(context);
+ * }
+ * </pre>
+ * <b>Example 2</b>: Process 50 events starting from the 1000th event
+ * <pre>
+ * int nbEventsRead = 0;
+ * ITmfContext context = trace.seekEvent(1000);
+ * ITmfEvent event = trace.getEvent(context);
+ * while (event != null && nbEventsRead < 50) {
+ * nbEventsRead++;
+ * // Do something ...
+ * event = trace.getEvent(context);
+ * }
+ * </pre>
+ * <b>Example 3</b>: Process the events between 2 timestamps (inclusive)
+ * <pre>
+ * ITmfTimestamp startTime = ...;
+ * ITmfTimestamp endTime = ...;
+ * ITmfContext context = trace.seekEvent(startTime);
+ * ITmfEvent event = trace.getEvent(context);
+ * while (event != null && event.getTimestamp().compareTo(endTime) <= 0) {
+ * // Do something ...
+ * event = trace.getEvent(context);
+ * }
+ * </pre>
*/
-public interface ITmfTrace<T extends ITmfEvent> extends ITmfComponent, Cloneable {
+public interface ITmfTrace<T extends ITmfEvent> extends ITmfDataProvider<T> {
// ------------------------------------------------------------------------
// Initializers
/**
* Initialize a newly instantiated "empty" trace object. This is used to
- * parameterize an ITmfTrace instantiated with its parameterless constructor.
+ * properly parameterize an ITmfTrace instantiated with its parameterless
+ * constructor.
+ *
+ * Typically, the parameterless constructor will provide the block size
+ * and its associated parser and indexer.
*
- * @param name the trace name
+ * @param resource the trace resource
* @param path the trace path
* @param type the trace event type
* @throws FileNotFoundException
*/
- public void initTrace(String name, String path, Class<T> type) throws FileNotFoundException;
+ public void initTrace(IResource resource, String path, Class<T> type) throws FileNotFoundException;
/**
* Validate that the trace is of the correct type.
*/
public boolean validate(IProject project, String path);
- /**
- * Set the resource used for persistent properties on this trace
- *
- * @param resource the properties resource
- */
- public void setResource(IResource resource);
-
// ------------------------------------------------------------------------
// Basic getters
// ------------------------------------------------------------------------
+ /**
+ * @return the trace event type
+ */
+ public Class<T> getType();
+
+ /**
+ * @return the associated trace resource
+ */
+ public IResource getResource();
+
/**
* @return the trace path
*/
public String getPath();
/**
- * @return the properties resource or null if none is set
+ * @return the trace cache size
*/
- public IResource getResource();
+ public int getCacheSize();
+
+ // ------------------------------------------------------------------------
+ // Trace characteristics getters
+ // ------------------------------------------------------------------------
/**
* @return the number of events in the trace
*/
public ITmfTimestamp getEndTime();
- /**
- * @return the streaming interval in ms (0 if not streaming)
- */
- public long getStreamingInterval();
+ // ------------------------------------------------------------------------
+ // Trace positioning getters
+ // ------------------------------------------------------------------------
/**
- * @return the trace index page size
+ * @return the current trace location
*/
- public int getIndexPageSize();
-
- // ------------------------------------------------------------------------
- // Indexing
- // ------------------------------------------------------------------------
+ public ITmfLocation<?> getCurrentLocation();
/**
- * Start the trace indexing, optionally wait for the index to be fully
- * built before returning.
+ * Returns the ratio (proportion) corresponding to the specified location.
*
- * @param waitForCompletion true for synchronous indexing
+ * @param location a trace specific location
+ * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
*/
- public void indexTrace(boolean waitForCompletion);
+ public double getLocationRatio(ITmfLocation<?> location);
// ------------------------------------------------------------------------
- // Seek operations
+ // Seek operations (returning a reading context)
// ------------------------------------------------------------------------
/**
* Position the trace at the specified location. The null location
- * is used to indicate that the first trace event.
- *
+ * is used to indicate that the first trace event is requested.
+ * <p>
+ * <ul>
+ * <li> a <b>null</b> location returns the context of the first event
+ * <li> an invalid location, including beyond the last event, returns a null context
+ * </ul>
+ * <p>
* @param location the trace specific location (null for 1st event)
* @return a context which can later be used to read the corresponding event
*/
/**
* Position the trace at the event located at the specified ratio in the
* trace file.
- *
+ * <p>
* The notion of ratio (0.0 <= r <= 1.0) is trace specific and left
* voluntarily vague. Typically, it would refer to the event proportional
- * rank or timestamp in the trace file.
+ * rank (arguably more intuitive) or timestamp in the trace file.
*
* @param ratio the proportional 'rank' in the trace
* @return a context which can later be used to read the corresponding event
/**
* Position the trace at the first event with the specified timestamp. If
* there is no event with the requested timestamp, a context pointing to
- * the chronologically next event is returned.
+ * the next chronological event is returned.
+ * <p>
+ * A null timestamp is interpreted as seeking for the first event of the
+ * trace.
+ * <p>
+ * If the requested timestamp is beyond the last trace event, the context
+ * returned will yield a null event if used in a subsequent read.
*
* @param timestamp the timestamp of desired event
* @return a context which can later be used to read the corresponding event
public ITmfContext seekEvent(ITmfTimestamp timestamp);
/**
- * Position the trace at the Nth event in the trace.
+ * Position the trace at the 'rank'th event in the trace.
+ * <p>
+ * If the requested rank is beyond the last trace event, the context
+ * returned will yield a null event if used in a subsequent read.
*
* @param rank the event rank
* @return a context which can later be used to read the corresponding event
public ITmfContext seekEvent(long rank);
// ------------------------------------------------------------------------
- // Read operations
+ // Read operations (returning an actual event)
// ------------------------------------------------------------------------
/**
* Return the event pointed by the supplied context (or null if no event
* left) and updates the context to point the next event.
*
- * @param context the read context
- * @return the next event in the stream
+ * @param context the read context (will be updated)
+ * @return the event pointed to by the context
*/
public ITmfEvent getNextEvent(ITmfContext context);
*/
public ITmfEvent parseEvent(ITmfContext context);
-
// ------------------------------------------------------------------------
- // Location operations
// ------------------------------------------------------------------------
/**
- * @return the current trace location
+ * @return the streaming interval in ms (0 if not a streaming trace)
*/
- public ITmfLocation<?> getCurrentLocation();
-
- /**
- * Returns the ratio (proportion) corresponding to the specified location.
- *
- * @param location a trace specific location
- * @return a floating-point number between 0.0 (beginning) and 1.0 (end)
- */
- public double getLocationRatio(ITmfLocation<?> location);
-
- /**
- * Returns the rank of the first event with the requested timestamp.
- * If none, returns the index of the subsequent event (if any).
- *
- * @param timestamp the requested event timestamp
- * @return the corresponding event rank
- */
- public long getRank(ITmfTimestamp timestamp);
-
- // ------------------------------------------------------------------------
- // Cloneable
- // ------------------------------------------------------------------------
-
- /**
- * @return a clone of the trace
- */
- public ITmfTrace<T> clone() throws CloneNotSupportedException;
+ public long getStreamingInterval();
}
projects / deliverable / tracecompass.git / blobdiff